Example on filtering nested non-list objects

There are a lot of examples on how to filter lists, but that doesn't seem to work on non-list objects.
Example:

``` json
{"a": 1, "b": {"c" : 100}}
```

If I want to filter by `c == 100` this will not work `b[?c==100]`. What should be used instead? Also how to filter by `a == 1`?